I made a bootable USB drive from a Kingston 16GB USB stick with Linux Mint 13 "Maya" - Xfce – 32-bit and I need to reformat the disk to do a fresh installation but I cannot clear the files. How do I do it? Thanks in advance for any help.

“You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete. “ Buckminster Fuller